Synchronism indicating means



Oct. 25, 1932. E. F. CARTER SYNCHRONISM INDICATING MEANS Filed July 22. 1927 Inventor: Emmett ECarter,

by HL; Attorney.

tors such as-thoseofthedistribntionsystem h p eyare f tobeused meted 0a. as, 1932 v UNITED s'rA Tss PATENT, OFFlCE wit CARTER, 0F BABY, YORK, ASSIlIGHOB TUBE-NM ELECTRIC comm, A OOBPORL'I'IOR O! m YORK mmca'rma IRA-I8 My invention relates to synchronism in dicatin means and more particularly to means or indicating a condition of synchrobetween a plurality of sources of volt- 5 age at a remote point by means of high frequency currents transmitted through space,.

or over wire line conductors such as those of the usual power distribution system.

It is often necessary in connection'with iu the operation of the usual power distribu- -9. D tion of the volta'e of .the generator-with respect to that o the system. It is neces-- sary to the synchronizin operationthat the y o rator should be relia ly informed as to e relative magnitude of the vbltage of the -generator with respect to that of the system, hsto whether the frequency 'of the genera-' tor being synchronized is greater or less than that of the system, as to the relative direcs tion ofphase rotation of the voltage of the 4:3 generator and'that of the system and finally 4 as to when the condition of chro has been'attained. Y

' One of the purposes of my preseht invenr tion is to pro ide means whereby the above iii- 85, dic'ations' may be had at the operators station in an economical; reliableandsatisfacspace, asbyradiqor ever .qofm to provide means whereby; a

had of meme. a further M on is .indications'may be 'hihfreq nency ere to ear at:8llabl0 0hlnn]8 be, con'uc rs orun acgasj 1 1813 ,eontroLor otherpup:

Arjuna filed July as. 1021. Io. mass.

The novel features which I, believe to be characteristic of {my-invention are set forth with particularity in' the appended claims. My invention itself, however, both as to its organization and method of operation to- 5;,

ther with further ob'ects and advantages 7 ereof may best be un erstood by reference to the followingdescription taken connection with the accompanying drawin in whichmthe single figure illustrates one em odicc ment of my invention.

Referrin to the drawing 1 indicates an electrical clrcuit which is s ownas of the polyphase type and which ma comprise'that 'of a single 'nerator or that oi the usual more as complicate distribution system. 2 representsa generator which may be located at a substation on the distribution system and which is adapted to be synchronized with and connected to the circuit 1 bymeans of a switch Ii 3. The uipment illustrated at A comprises that whizh is located at the substation, or in the neighborhood of the generator 2, and that which 1s illustrated at B comprises the equip- .m'ent located atthe operator s or power d1s-- filxzltchers station. For the urpose of controlg the generator 2 and e switch 3 by the operator at'the station B any suitable type of remote control equipment, not shown, may be employed. Sincemy invention relates only It to means for the required indications at the station B the necessary control equipment will not be here set forth.

A the station A. is locatedJa'n oscillation generator. 4 whieh'is adapted through the cou- 88 plingcondenser 5 to supply high frequency 591') manner. Another p u "of my inven alternating currents to t e grid circuit of an tron is to provide means M. -the ahov'e amplifier 6 the-output circuit of which is mdieationsma behadhygleauaef throughatransformer Tandcon quency curl-en -tramnm .1 m ductor's' 8 to the circuit 1. The oscillation an"ductors 11 to one ph s s c-2 4 a 12,18, 14 regrflesent transformers 'corre-' tq-the number of phases of the rator 2 and circuit 1. The primary windin of each of these transformers plied from the devices 18, 19

is connected t rough conductors 15, 16, 17 respectively to corresponding phases of the generator 2 and circuit 1 and across each phase of the connecting device 3. Associated with the secondary circuit of each of these transformers is a rectifyin device 18, 19, 20 respectivel each of whic may be of the usual two e ement electron discharge type and which are connected in a manner to supply rectified potential from the transformers 12, 13, 14 to the anode circuit of the oscillation generator 4 and the amplifier 6. The circuit of these devices includes the spaces between the cathodes and anodes of these devices, secondary windings of the transformers 12, 13, 14, conductor 21, conductor 22, conductor '23 cathode circuit 9 of the oscillation generator 4 and amplifier 6, spaces between the cathodes and anodes of the generator 4 and amplifier 6, anode reactors. 24 and 25, and the cathode circuit of the devices 18, 19, 20. This latter cathode circuit is likewise energized through the transformer 27 from the conductors 11. It will thus be seen that at anyin'stant when an alternating current potential appears across any pair of contacts of the polyphase switch 3 direct current potential will be su circuit previously traced to the anodes of the oscillation enerator 4iand the amplifier 6,

- thereby ren ering these devices operative to sup ly high fre uen currents of roportion dte ma itu e thi ough the transformer 7 and'circult 8 to the distrlbutionsystem 1.

At the remote point, or dispatchers station B, is provided a detector, or rectifying device 28, which may also be of the three element discharge type "and which is connected on cuit 31 to the distribution circuit 1. The circuit 29 includes suitable inductance 32 and condenser 33 by means .of which it may be tuned to the fre uency of the carrier currents transmitted by e generator 4 and amplifier 6. In the anode circuit of the device 28 is connected a direct current indicating means 34, primary winding of the transformer 35 and the usual source of anode potential 36.

With the equipment as thus far described,

cuit of the devices 4 and 6, rendering them operative to supply pulsations of high freglliency current to the'circuit 1 and hence to e rectifying device 28, thereby producing a response upon the indicating device 34. The frequency of the pulsations will be equal to 20 through t e gh a circuit 29, transformer 30and cirfrom one phase at right the beat frequency between the volta es of the sources 1 and 2, with the result t at as synchronism is gradually approached the needle of the ammeter 34 will be seen to vibrate back and forth over its scale between limits determined by the maximum and minimum magnitudes of the received carrier and with a frequency which is directly indicative of the difference between the frequencies of the two sources. By this means the o erator is informed as to the proper time to c ose the switch 3; namel when the vibrations of the needle are sufliclently infrequent to indicate that synchronism has been practically attained and when the needle registers a min mum of received carrier.

If the phase rotation of the source 2 happens 'to be reversed from that of the. volta e on the circuit 1 then plate voltage will fie continuously applied to the anode circuit of the devices 4 and 6, there being small periodic pulsations therein which are of high frequenc and small magnitude as compared with t e pulsations which occur when the directions of phase rotation are alike. Thus the meter 34, when the phase rotations are in opposite directions, will register a plate current which has a magnitude intermediate the maximum and minimum which occurs when the direction of phase rotation are alike and also having a considerably smaller average value. This current will also have smaller pulsations therein than is the case when these hase rotations are alike, these characteristics indicating to the operator that the phase rotation of the machine 2 is incorrect.

It wil1 thus be seen that with the arrangement as thus far described, the operator is furnished with an indication as to the proper direction of phaserotation ofthe voltage of the source 2 andalso with an indication as to when the two voltages are in chronism and of roper relative magnitu e if the directions of base rotations are alike. It is also desira is that the operator be furnished with information as to whether the machine 2 is running-too fast or too slow so that he'may be informed as to what adjustments are necessary in order to bring the machine 2 into synchronism. To this end' a device 37 is provided which ma if desired, comprise a .synchronoscope o 'well known construction, such as that disclosed in Patout No. 685,155 P. M. Lincoln or any other suitable means 0 erable responsively to the relative frequencies 'of the sources 1 and 2. A. stationary coil 38 which is wound upon a. U-shaped ma eticcoreg89'is energized of the giperator 2. Two rotatable coils 40 and 41 w ch are disposed lee to each other are located'in inductive ation to the coil 38 and the magnetic core 39, the former of these coils being connected across a phase of the circuit 1 corresponding to phase 65 of the source 2 resume through an inductance 42 and the latter being connected to the same phase through a resistance 43. Since this arrangement is now well-known in the art a further description thereof will not be iven. Mountedupon the axis of the rotata 1e coils 40 and 41 and adapted to rotate therewith is a disc 44. 45 represents an arm which is pivoted at its mid-point about a point near the circumference of the disc 44 one end of which frictionally engages the disc 44 and the other end of which is free. On opposite sides of the free end of the arm 45 are two pairs of contacts 47 and 48, the arrangement being such that if the coils 40 and 41, and therefore the disc44, rotate in a clockwise direction, as would be caused if the frequency of the source 2 were greater than that of the circuit 1, then the contacts 47 will be pressed into engagement by means of the arm 45, whereas if the rotation of the coils 40 and 41, and therefore the disc 44, be in a counterclockwise directionas would be the case if the fregluency of the source 2 were less than that of t e circuit 1, then the contacts 48 will be pressed into engagement. The purpose of this will presently be set forth. 49 represents a constant speed motor on the shaft of which is mounted a slip rin 50 and a pair of commutators 51 and 52. ach of these commutators comprises a plurality of conducting segments which are separated from each other about the circumference of the commutator by suitable insulation, and each of which are electrically connected to the slip ring 50. The commutator 51 is connected in a circuit leading from slip ring 50 through the primary wind- 7 mg of the modulation transformer 53, source of potential 54, conductdr 55, contacts of the relay 56, conductor 57 and brush 66 which engages the commutator 51. The commutator 52 is connected in a circuit leading from the collector ring 50 through the primary winding of the modulation transformer 53, source of potential 54, conductor 55, contacts of the relay 58, conductor 59 and brush 67 which engages the commutator 52. The secondary winding of the modulation trans former 58 is connected between the cathode and the grid of the amplifier 6. The actuating coils of the relays 56 and 58 are adapted to be energized through circuits including the contacts 47 and 48 respectively, conductor 60. source of potential 54 and conductor 55. The contacts of these relays are preferably slightly slow in opening, this feature rendering the relays less sensitive to chattering of the contacts 47 and 48. The operation of thisportion of my device is as follows. If it be assumed that the frequency of the source of potential 2 is greater than that of the voltage on the circuit 1, then the disc 44 will rotate in 'a clockwise direction, thereb through the arm 45 causing the contacts 4 to beclosed and energizing the relay 56.

This relay then closes its contacts, thereby energizing the circuit of the primary winding of modulation transformer 53 through the collector ring 50 and commutator 51, and causing the output current transmitted from the amplifier 6 to be modulated by currents determined in character by the spacigg of the se ments of the commutator 51. ikewise i the frequency of the source 2 be less than'that of the voltageof the circuit 1 then the disc 44 will rotate in a countercloc wise direction and the arm 45 will be actuated to close the contacts 48, and thereby energize the relay 58. The rela 58 then closes its contacts to energize the circuit of the primary windin of the modulation transformer 53 throng the collector ring 50 and the commutator 52, thereby causing the output current fromthe amplifier 6 to be modulated by currents determined in character by the spacing of the segments of the commutator 52. Thus, for exam le, if it be supposed that the segments of the commutators 51 and 52 are equall spaced about the circumference but that t e segments of the commutator 51 aregreater in number than those of the commutator 52 the two commutators being of equal diameter, it will be seen that when the frequency of the generator 2 is greater than that of the circuit 1, the output currents from the amplifier 6 will nating currents of a certa? n frequency, whereas if the frequency of the source 2 be less than that 'of the circuit l'then the output current from the amplifier 6 will be modulated by alternating currents of a certain lesser frequency. Associated with the secondary winding of the transformer 35 in the output circuit of the rectifier 28 at the receiver are any suitable means 61 and 62 for indicatin to the operator the character of the modu ating currents. This may constitute an audible device such as a pair of head phones, or, for example, in the case supposed above, where the modulating currents are distinguished in character by the frequency the device 61 may comprise a tuned relay operable responsively to the modulating freguency when the generator 2 is running too ast and the device 62 may comprise a tuned responsively to the modulating frequency when the generator 2 is running too slow. If desired the device 61 may be caused to energize a visible indicating device 63 and the device 62 may be-caused to energize a visable indicating device 64, the former being efl'ected throu h conductor 68, source of potential 69 an conductor 70; and the latter being efiected through conductor 68, sources of potential 69 and conductor 71. i It will thus be seen that the operator at the station B by observing the magnitude of the received carrier and that of the pulsations therein as indicated, by the indicating relay operable be modulated by alterdevice 34 may determine the direction of base rotation of the machine 2, and if this irection be correct he may determine when the condition of synchronism has been attained. Likewise by means of devices 61 and 62, or if desired, by devices 63 and 64, he may determine respectivel whether the generator 2 be running too ast or too slow. Consequently, it will be noted that with my device as shown and described, the operator at a remote station B is furnished with all of the indications necessary to the synchronizing operation and that he is thereby enabled by means of his remote control equipment to control the generator 2 and the switch 3 in a manner such that the generator 2 may be safely connected to the circuit 1.

While I have shown a particular means for modulating the carrier it will, of course, be understood that any suitable means may be employed. Likewise while I have shown a particular device 37 for operatin the con tacts 47 and 48 it will, of course, e understood that any means which is operable responsively to the relative frequency of the source 2 and the circuit 1 may be used. In a similar manner I have shown means for varying the intensity of the carrier in accordance with the voltage across the connectin means 3. It will, of course, be understood 518i? any means for varyin the carrier in a known relation to the V0 tage across this connecting means may be employed.

While I have shown and described a particular embodiment of my invention, it will, of course, be understood that I do not wish to be limited thereto since many modifications both in the circuit arrangement and in the instrumentalities employed ma be made without departing from the spirit and scope of my invention as set forth in the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In combination, an alternating current circuit, an alternating current generator adapted to be connected thereto, ennnecting means therefor, a transmitter connected to transmit high frequency currents varying in intensity responsively to the voltage across said connectin means and means responsive to said high requency currents.

2. In combination, an alternating current circuit, an alternating current generator adapted to be connected thereto, connecting means therefor, a transmitter, means for continuously varying the intensity of the output from said transmitter responsively to the voltage across said connecting means, and means at a remote point ada ted to be supplied with currents from sai transmitter.

3. In combination, an alternating current circuit, an alternating current generator adapted to be connected thereto, connecting means therefor, a transmitter of alternating current-s adapted to be energized responsively to the voltage across said connecting means, thereby to transmit alternating currents varying m intensit in accordance with the voltage across sai connecting means, rectifyin means for said alternating currents an indicating means responsive to the rectified current to indicate the condition of voltage across said connecting means. 4. In combination, an alternating current circuit, an alternating current generator adapted to be connected thereto, connecting means therefor, a transmitter, means for varying the output currents from said transmitter in a known relation to the voltage across said connecting means, additional means for modulating the output currents from said transmitter in accordance with the relative frequency of the voltages appearing on opposite sides of said connecting means and means at a remote point responsive to said modulated output currents. 5. The combination, with a plurality of alternating current sources adapted to be synchronized with each other, of means for interconnecting said sources, a vacuum tube transmitter, means for energizing the anode circuit of said transmitter in response to the voltage across said interconnecting means, and means responsive to the output currents from said transmitter.

6. The combination, with a plurality of alternating, current sources ada ted to be synchronized with each other, 0 means for interconnecting said sources, a vacuum tube transmitter of high frequency currents, means for energizing the anode circuit of said transmitter in accordance with'the voltage across said interconnecting means, means for producing variations in said high frequency currents determined in character by the relative f uency 0t voltages on opposite sides of sai interconnecting means and means at a remote pointresponsive to the intensity of said high frequency currents and to said variations.

7. The combination, with a plurality of alternating current sources adapted to be synchronized'with each other, of means for interconnecting said sources, a high frequency transmltter of the electron discharge type, rectifying means adapted to be energ gized in accordance with the voltage appearmg across said interconnecting 'means for supplyin' anode potential dependent thereon to sai transmitter and means at a remote point responsive to the intensi of the high requency currents transmitted y said transmitter. I

8. In combination, a circuit havin 'alternating current potential impressed t ereon, an alternating current generator, means for connecting said generator to said circuit, a carrier current transmitter, means for varying the output from said transmitter in accordanoe with the voltage across said connecting means, means for modulating said carrier currents with currents having either of two characters dependent upon whether the frequency of said generator be greater or less than that of said circuit and means at a remote point responsive to the intensit of said carrier and the character of sai modulating currents.

9. In combination, a circuithaving alternating current voltage impressed thereon, an alternating current generator, means for connecting said generator to said circuit, a carrier current transmitter, means for varying the output from said transmitter in accordance with the voltage across said connecting means, means for modulating said transmitter operable when the frequengy of said generator is greater than that said circuit, 10 means for modulatin said transmitter operable when the Irequency of said generator is less than that of said circuit, each of said modulating means being adapted to produce variations in said carrier of a I5 different character and means at a remote point responsive to the intensity of said car- 'riei'and the character of said variations.

10. In combination, a circuit having alternating current voltage impressed thereon, an alternating current generator, means for connecting said generator to said circuit, a carrier current transmitter, means for varying the output from said transmitter in accordance with the voltage across said connecting means, a plurality of means for producing variations in said carrier of difierent characters, means responsive to frequencies of said generator greater than that of said circuit for establis ing an operative circuit for one of said last mentioned means, and to frequencies of said generator less than that of said circuit for establishing an operative circuit to another of said last mentioned means and means at a remote point responsive to theintensity of said carrier and the character of said variations.

11. In combination, a circuit having alternating current voltage impressed thereon, an alternating current generator, means for connecting said generator to said circuit, a carrier current transmitter, means for varying the out ut from said transmitter in accordance with the voltage across said connecting means, means rents with currents having either of two frequencies dependent upon whether the freuency of said generator be greater or less t an that of said circuit, and indicating means at a remote 'point responsive to the intensity of said carrier and to the frequency of said modulating currents.

12. The combination, polyphase alternating current sources adapted to be synchronized with each other, of means for interconnecting said sources, a

for modulating said carrier curwith a plurality of carrier transmitter, a plurality of transforme'rs, the prima winding of each of said transformers being connected between corresponding phases of said sources across said interconnecting means, rectifying means associated with the secondaries of each of said transformers and adapted to energize said transmitter in accordance with the voltage across said interconnecting means, means for producing variations in said carrier currents determined in character b the -relative frequency of the voltages 0 said sources and indicating means responsive to the intensit of said carrier and t0 the character of sai variations.

13. In combination, a plurality of polyphase alternating current sources, a carrier current transmitter and means for energizin said transmitter in a manner determined y the relative direction of phase rotation of said sources.

14. In combination, a plurality of polyphase alternating current sources, a carrier currenttransmitter and means for varying the output from said transmitter in accordance with the relative frequency and direction of phase rotation of said sources.

15.In combination, a circuit having alternating current impressed thereon, an alternating current source adapted to be connected thereto, a transmitter, means for varying the output currents from-said transmitter in accordance with the relative, uency of the voltages of said source and sai circuit, and means for additionally varying said output currents in either of two manners de ndent upon whether the frequency of sai source be,greater or less than that of said circuit.

16. In combination, a plurality of polyphase alternating current sources, a transmitter, means for varyin ,the output currents from said transmitter in accordance with the relative directions of phase rotation of said sources, and means for modulatin said outut currents in accordance with t e relative uency of said sourc 1 In combination, a line havingb alternating electromotive force impressed ereon,

an alternating current source to be synchronized with said line, an electron discharge device having an output circuit, means for energizing said discharge device in response to I a resultant of electromotive forces of said source and line, a device, and means for controlling said device in response to current in said output circuit.

18. In combination, a source of alternating electromotiveforce, a second source of alternating electromotive force, switching means for connecting said sources tcgether, a transformer having a prima winding and a secondary winding, one si e of said primary winding being connected across sai switching means, means for rectifying the voltage across the secondary of said transformer, a second transformer energized with alternating currents, and means for controlling the output current from said second transformer in response to said rectified current.

19. In combination, a source of alternating electromotive force, a second source of alternating electrornotive force, switching means for connecting said sources together, means for rectifying the potential existing between said sources, a thermionic discharge device having an output circuit, and means for controlling the current in said output circuit in response to rectified current produced by said rectifying means.

20. In combination,-a plurality of alternating current sources, a high frequency transmltter arranged to transmit a carrier wave having a-constant frequency, and means for modulatin said carrier wave in a manner determine by the relative frequency of said sources.

21. In combination, a plurality of polyphase alternating current sources, a high frequency transmitter, and means for controlling the output current from said transmitter in response to the relative direction of phase rotation of said sources.

22. In combination, a pair of sources of alternating current, acarrier wave transmitter, and means for modulating the carrier wave transmitted by said transmitter in either of two difi'erent manners dependent upon the relative frequency of said sources, said carrier wave being modulated in one of said manners when the frequenc of one of said sources is higher than that o the other and in a different manner when the frequency of said one source is lower than that of the other.

In witness whereof, I have hereunto set my hand this 21st day'of Jul 1927.

EMMETT CARTER.

CERTIFICATE or common.

Patent No. 1,885,078. October 25. 1932.

mam F. CARTER.

ror appears in the printed specification of the ng correction as follows: Page 2, line 109, for "rotations" read "rotstion"; page 5, line 66, claim 12, after "carrier" insert the word "current"; and line 94, claim 15, after "current" insert the word voltage; and that the said Letters Patent should be read with thae corrections therein that the some may conform to the record of the case in the Patent 0flce.

Signed and sealed this 29th day of November, A. l). 1932.

It is hereby certified that er shove numbered patent requiri a. J. Moore,

(Seal) Acting Cousnissioner of Patents.

former, a second transformer energized with alternating currents, and means for controlling the output current from said second transformer in response to said rectified current.

19. In combination, a source of alternating electromotive force, a second source of alternating electrornotive force, switching means for connecting said sources together, means for rectifying the potential existing between said sources, a thermionic discharge device having an output circuit, and means for controlling the current in said output circuit in response to rectified current produced by said rectifying means.

20. In combination,-a plurality of alternating current sources, a high frequency transmltter arranged to transmit a carrier wave having a-constant frequency, and means for modulatin said carrier wave in a manner determine by the relative frequency of said sources.

21. In combination, a plurality of polyphase alternating current sources, a high frequency transmitter, and means for controlling the output current from said transmitter in response to the relative direction of phase rotation of said sources.

22. In combination, a pair of sources of alternating current, acarrier wave transmitter, and means for modulating the carrier wave transmitted by said transmitter in either of two difi'erent manners dependent upon the relative frequency of said sources, said carrier wave being modulated in one of said manners when the frequenc of one of said sources is higher than that o the other and in a different manner when the frequency of said one source is lower than that of the other.

In witness whereof, I have hereunto set my hand this 21st day'of Jul 1927.

EMMETT CARTER.

CERTIFICATE or common.

Patent No. 1,885,078. October 25. 1932.

mam F. CARTER.

ror appears in the printed specification of the ng correction as follows: Page 2, line 109, for "rotations" read "rotstion"; page 5, line 66, claim 12, after "carrier" insert the word "current"; and line 94, claim 15, after "current" insert the word voltage; and that the said Letters Patent should be read with thae corrections therein that the some may conform to the record of the case in the Patent 0flce.

Signed and sealed this 29th day of November, A. l). 1932.

It is hereby certified that er shove numbered patent requiri a. J. Moore,

(Seal) Acting Cousnissioner of Patents. 

